Reovirus infections associated with high mortality in psittaciformes in The Netherlands

Abstract

In The Netherlands between January 2002 and December 2004, numerous psittaciformes died showing severe splenomegaly and hepatomegaly with multifocal acute necrosis. At the start of the outbreaks mostly parakeets were affected, but later larger parrots were also involved. Seventy-eight birds showed the same features and six were examined completely, including a virological examination. Tests for polyomavirus, Pacheco's disease (herpesvirus) and circovirus psittacine beak and feather disease (PBFD) viruses and Chlamydophila psittaci were carried out. All results were negative, except for two cases of circovirus infection. Many concurrent bacterial and parasitic infections were seen. Immunohistochemistry revealed reovirus antigen in intralesional mononuclear cells, and reovirus-like particles could be observed by negative contrast electron microscopy. A reovirus was grown and the isolates reacted with polyclonal reovirus antiserum but did not react with monoclonal antibodies against chicken reovirus. The virus was therefore considered a psittacine reovirus. Because reoviruses were seen consistently, they seemed to be the most probable cause of the outbreaks. Climate, the introduction of new birds and the transportation of birds might be other factors involved in the disease seen in The Netherlands. No regional influence could be seen; therefore, we suggested that the virus might be widespread and carriers could be a source of re-introduction.

Postvaccinal Reovirus Infection with High Mortality in Breeder Chicks

“…Hepatic necrosis is a feature of natural reovirus infection in young chicks, poults, and psittacines (2,12,14). Moreover, the lesions in the myocardium are similar, although less severe, to those reported in turkey poults and broiler breeder chick infected by a reovirus (12).…”

Whole-genome analysis of piscine reovirus (PRV) shows PRV represents a new genus in family Reoviridae and its genome segment S1 sequences group it into two separate sub-genotypes

“…The Orthoreovirus genus can be divided into the fusogenic and non-fusogenic orthoreoviruses based on the ability of the fusogenic orthoreoviruses to induce cell-cell fusion during infection resulting in syncytium formation [3] by virtue of possession of a fusion-associated small transmembrane (FAST) protein [4]. Whereas the non-fusogenic orthoreoviruses, Mammalian Orthoreovirus (MRV), are not clinically significant [5], the fusogenic orthoreoviruses Nelson Bay virus (NBV) [6] and Baboon Orthoreovirus (BRV) [7] that infect primates, Avian Orthoreovirus (ARV) [8] that infect birds, and Reptilian Orthoreovirus (RRV) [9] that infect reptiles, have been shown to cause significant and often fatal disease. Most recently, PRV has been shown to be more closely related with recognized orthoreoviruses than with recognized aquareoviruses, and does not encode a FAST protein and is therefore non-fusogenic [10].…”

A Review of DNA Viral Infections in Psittacine Birds

“…Today, infectious diseases, especially viral infectious diseases, are the most common clinical problems in captive psittacine birds because of their association with acute death and difficulties in treatment and control. Many viral infections in psittacine birds have been reported, including DNA virus: psittacine beak and feather disease (PBFD) [73], avian polyomavirus infection (APV) [5], psittacid herpesvirus infection (PsHV) [92], psittacine adenovirus infection (PsAdV) [81], poxvirus infection [58], and papillomavirus infection [14] and RNA virus: reovirus infection [106], coronavirus infection [26], paramyxovirus infection [29], influenzavirus infection [76], and bornavirus infection [50]. However, information about these diseases is limited.…”